Airbag, in particular for a side curtain airbag system, and vehicle safety system having such an airbag

ABSTRACT

The invention relates to an airbag ( 10 ), especially for a side curtain airbag system ( 20 ), comprising an airbag interior ( 30 ) which in the deployed state of the airbag ( 10 ) defines one single chamber ( 40 ), wherein the chamber ( 40 ) comprises a gas guiding device ( 50 ) by which the chamber ( 40 ) is divided into at least one primary filling zone ( 41 ) and at least one secondary filling zone ( 42 ), as well as to a vehicle safety system equipped with such airbag ( 10 ).

RELATED APPLICATIONS

This application is a divisional application of U.S. application Ser.No. 16/311,838, filed Dec. 20, 2018, which corresponds toPCT/EP2017/066927, filed Jul. 5, 2017, which claims the benefit ofGerman Application No. 10 2016 008 241.0, filed Jul. 7, 2016, thesubject matter of each of which are incorporated herein by reference intheir entirety.

BACKGROUND OF THE INVENTION

The invention relates to an airbag, especially for a side curtain airbagsystem according to the preamble of claim 1, as well as to a vehiclesafety system equipped with such airbag according to the preamble ofclaim 10.

Airbags for airbag systems, especially for side curtain airbag systems,have been known for some time. Airbag systems of this type serve forbetter protecting occupants of an automotive vehicle in the case ofaccident. For this purpose, a side curtain airbag system is arrangedabove a side window and in the case of crash deploys downwards in acurtain-like manner so as to better protect a head and shoulder area ofa vehicle occupant against a side impact.

One drawback of these previously known side curtain airbag systemsconsists in the fact that they do not cover a thorax area of the vehicleoccupant and a separate airbag (thorax airbag) has to be provided so asto obtain better protection also in the thorax area.

If the known side curtain airbag system was modified so that it wouldextend in the vertical direction further downwards, i.e. beyond theshoulder area and into an area on the side of the thorax of a vehicleoccupant so as to protect in this way also the thorax area of a vehicleoccupant by one airbag only for each vehicle occupant, a new problemwould arise, namely a significantly larger airbag volume and,accordingly, the problem of managing a filling of such large airbagexactly in time and to the correct volume. This would be especiallydifficult, as the airbag is successively filled starting from theinflator provided for filling the airbag and being arranged either in apillar or in the roof of a vehicle, wherein, according to theconstruction, at first the “curtain sections” of the airbag locatedfurther upwards and more closely to the gas supply are filled and onlyat last the section located further downwards which is provided forprotecting the thorax is filled.

For this reason, in the past also airbag systems were suggested whichprotected the thorax area of a vehicle occupant with the aid of a secondairbag.

However, it is a drawback of those airbag systems and, resp., airbags tofill the different airbag chambers or airbags in a way adapted in timeso that the chambers or airbags are correctly filled and correctlypositioned at the correct time for ensuring optimum occupant protection.

Airbag systems of this type are described, for example, in WO2008/011414 A2, U.S. Pat. No. 7,350,804 B2 or US 2005/0134025 A1.

SUMMARY OF THE INVENTION

The object underlying the invention is to provide an airbag (for eachvehicle occupant), especially for a side curtain airbag system, as wellas a vehicle safety system being equipped with such airbag, whileavoiding the afore-mentioned drawbacks, wherein the airbag volume isfilled with gas in terms of time and space such that an optimizedoccupant protection is ensured.

This object is achieved by an airbag, especially for a side curtainairbag system, according to claim 1 as well as by a vehicle safetysystem according to claim 10 which is equipped with such airbag.

In particular, the object is achieved by an airbag, especially for aside curtain airbag system, wherein the airbag includes an airbaginterior defining one single chamber in the deployed state of theairbag, the chamber having at least one gas guiding device by which thechamber is divided into at least one primary filling zone and at leastone secondary filling zone.

It is a major point of the invention that, by way of the gas guidingdevice arranged inside the volume of the airbag within the airbaginterior, a filling of the airbag volume controlled both as to space andas to time is possible starting from a fluid source, especially gassource, such as an inflator. For this purpose, the gas guiding devicedivides the airbag interior and, resp., the chamber of the airbagforming the airbag interior into at least one primary filling zone andinto at least one secondary filling zone.

When gas is supplied into the airbag interior, the gas is thus guidedalong the gas guiding device first into the primary filling zone. Asupply of gas into the secondary filling zone is substantially notcarried out before a particular primary filling level is reached.

According to a preferred embodiment of the invention, the primaryfilling zone(s), i.e. at least one primary filling zone, is/are moredistant in the spatial and fluidic respect from the single or at leastone gas supply orifice through which gas supply of the airbag may takeplace, than the secondary filling zone(s) is/are distant from therespective same gas supply orifice.

In this context it is mentioned that the primary filling zone(s)according to a preferred embodiment of the invention is/are associatedwith the portion of the airbag that is provided for protecting thethorax, while the secondary filling zone(s) is/are associated with the,especially upper, “curtain section” of the airbag.

The gas guiding device according to the invention causes the respectiveprimary filling zone(s) arranged spatially more distant from the gassupply orifice to have a smaller distance from the gas supply orifice inthe fluidic respect than the respective secondary filling zone(s)has/have from the respective same gas supply orifice so that duringfilling the airbag according to the invention at first the primaryfilling zones and only afterwards the secondary filling zones are filledwith gas.

In accordance with a preferred embodiment of the invention, this iseffectuated in that the gas guiding device is configured so that itforms a separation, namely a separating device such as a separating wallor a separating seam between the primary filling zones and the secondaryfilling zones or, respectively, between the primary filling zone and thesecondary filling zone.

The gas guiding device and, resp., the separating device is configuredto be substantially impervious to gas for this purpose so that uponfilling the airbag the gas flowing from the gas supply orifice into theairbag is guided along the separating device into the primary fillingzone. The separating device thus delimits the primary filling zoneagainst the secondary filling zone, wherein a complete, especiallysubstantially gas-tight, separation of the two filling zones may berealized or a defined gas-permeable separation of the primary fillingzone from the secondary filling zone is given so that a small portion ofthe inflowing gas along the separating device may flow through the samealso into the secondary filling zone so that the latter is filledsimultaneously with the primary filling zone, however by a definitelyreduced volume flow. The reduced volume flow is within the range of 1%to 20%, preferably within the range of 2% to 15% and especiallypreferred within the range of 5% to 10%, each related to the inflowingtotal volume flow of the inflowing filling gas.

In accordance with an embodiment of the invention, the gas guidingdevice is formed in that at least two inner wall portions of the airbagfacing each other and being associated with each other areinterconnected directly or by means of a spacer, especially by means ofa spacing belt, preferably in a detachable manner. The connection of theinner wall portions of the airbag associated with each other isrealized, according to the invention, by means of a seam which may be aglued seam and/or a sealed seam and/or a stitched seam. In the case ofuse of a spacer, especially a spacer belt, the respective inner wallportions of the airbag are not connected directly but via the spacerbelt, wherein the respective longitudinal sides and, resp., longitudinaledges of the spacer belt are again connected by means of a seam, whichagain may be a glued seam and/or a sealed seam and/or a stitched seam,to the pertaining, i.e. associated, inner wall portions of the airbag.

According to the invention, the spacer belt in turn may be configured tobe gas-permeable or to have a defined gas permeability so that during afilling operation of the airbag according to the invention a main volumeflow flows in the direction of the primary filling zone and a reducedsecondary volume flow flows in the direction of the secondary fillingzone. By the degree of gas permeability of the separating device aspecific control in terms of time and space of the filling operation ofthe airbag according to the invention is possible, wherein the gaspermeability of the separating device may be different over its length.At this point, also an initial gas permeability of the separatingdevice, which is provided already at the beginning of the fillingoperation of the airbag, has to be distinguished from initiated gaspermeability according to the invention which is resulting, for example,from a widening of pores or holes in the separating device during thefilling operation.

In accordance with a preferred embodiment of the invention, theconnection of the inner wall portions of the airbag associated with eachother which forms the separation between the primary filling zone andthe secondary filling zone is designed to be detachable so that theconnection is released and, resp., opened upon increase in the internalpressure inside the airbag in the course of filling the airbag, forexample, so that gas may flow through this releasing connection, i.e.opening separation, from the gas supply orifice and moreover from theprimary filling zone into the secondary filling zone so that now alsothe secondary filling zone fills substantially completely with fillinggas. In the case of using a spacer belt, a longitudinal edge of the beltmay remain tightly connected to the associated inner wall of the airbag,while upon breaking of the connection the other longitudinal edge of thebelt detaches from the associated inner wall portion of the airbag.

In accordance with the invention, the glued and/or sealed and/orstitched seam may have a different seam resistance. Such different seamresistance may be realized, for example, by a differently broad gluingand/or sealing and/or stitching. Moreover, also differently tightadhesives, sealing materials or yarns may be used. The respective typesof connection may also be used in combination with each other andsupplementing each other.

In addition, the seam may have at least one weakened portion serving asa predetermined breaking point for the seam. Such weakened portion maybe in the form of a pointed seam, for example, which projects into thearea of higher pressure during the filling operation of the airbag andpeels and/or tears upon reaching a particular minimum pressure. Byproviding such weakened portion a breaking of the seam canadvantageously be exactly controlled, wherein it is possible, forexample, to define the point or points of the seam at which a breakingof the seam will be initiated or will start.

According to a further preferred embodiment of the invention, the gasguiding device is formed by a tubing system having at least one inletopening and at least one outlet opening, the inlet opening being influid connection with the at least one gas supply orifice of the airbagand the at least one outlet opening ending in the primary filling zoneof the chamber. According to the invention, it is advantageouslypossible to supply the filling fluid and, resp., gas to the volume ofthe airbag, i.e. the one or the plural primary filling zone(s) and theone or the plural secondary filling zone(s) through the tubing system sothat at first the one or the plural primary filling zone(s) are filledwith the filling fluid, as the outlet opening of the tubing system endsin the one or the respective primary filling zone(s) and only afterwardsthe gas flows via said primary filling zones into the secondary fillingzone(s) of the airbag according to the invention and fills the latter.

According to the invention, the tubing system through which the gas isguided may be substantially completely gas-tight or may have a certainpermeability for the inflowing gas so that a reduced volume flow mayflow out of the tubing system directly into the one or the, possiblyselected, secondary filling zone(s), wherein the reduced volume flow isin the range of from 1% to 20%, preferably in the range of from 2% to15% and especially preferred in the range of from 5% to 10%, in eachcase related to the total volume flow of the inflowing filling gas.

In this way it is possible to fill both the primary filling zones andthe secondary filling zones exactly at the desired time with therespectively desired amount of gas so that a filling targeted in termsof space and time of the airbag takes place.

Moreover, the tubing system may have a weakened point, for example inthe form of a seam, which may be a sealed seam and/or a glued seamand/or a stitched seam, so that the tubing system will burst at one ormore positions or else substantially completely when a predeterminedfilling state of the airbag is given. Such filling state of the airbagmay be defined, for instance, via a predefined pressure prevailing inthe primary filling zone and/or in the secondary filling zone and/or inthe tubing system. It is stated in this context that also the airbagwall itself may be designed as part of the tubing system and may formpart of the wall of the tubing system, for example.

For the rest, the tubing system may be guided along the inner wall ofthe airbag and/or be fastened on said inner wall, by means of spacerswhere necessary.

According to a further embodiment of the invention, the spacer,especially the spacer belt, and/or the tubing system is madesubstantially of the same material as the airbag.

Further the object according to the invention is achieved also by theuse of an airbag for an airbag system, especially a side curtain airbagsystem, according to the foregoing remarks.

The object according to the invention is further achieved also by amethod of filling an airbag, wherein gas is introduced into the airbagstarting from a gas supply orifice using a gas guiding device accordingto the foregoing description, wherein before filling a secondary fillingzone at first a primary filling zone is filled at least partly orsubstantially completely with gas.

In the course of feeding the secondary filling zone with gas, accordingto the invention, at least one separating device, especially at leastone seam will be broken between the primary filling zone and thesecondary filling zone of the chamber. The separation is substantiallybroken so far that the airbag interior in the deployed, i.e. in thesubstantially completely filled state of the airbag defines one singlechamber.

Furthermore, the object according to the invention is also achieved by avehicle safety system that is equipped with an airbag according to theforegoing description and is fed with gas by the afore-described methodfor filling such airbag. Such vehicle safety system includes at leastone sensor unit for detecting data as well as an electronicdecision-making unit which is adapted, while incorporating the datadetected by the sensor unit, to define the presence of a trigger casefor the airbag module and/or to send a trigger signal to the airbagmodule.

Summing up, the invention discloses a curtain airbag comprising a thoraxprotection, wherein the airbag has a specific airbag design according tothe invention for quicker targeted and time-optimized deployment so asto optimally position the airbag for ensuring optimized occupantprotection, especially in the case of side impact. The substantialaspect of the invention consists in the fact that the side curtainairbag including thorax protection is deployed so that the gas escapingfrom the propellant and possibly from a gas storage system is initiallyguided into the part of the airbag which is essential for the thoraxprotection, i.e. the lower part in the mounted and, resp., deployedstate. According to an embodiment of the invention, this is obtained byway of a seam or plural seams and/or a tubing system arranged to beintegrated in the airbag and serving as a gas guiding device. The seamor, respectively, the plural seams, is/are configured as regards theirstrength so that upon a predetermined degree of deployment and of thedeployment volume of the airbag they will tear in the thorax area sothat the gas may diffuse through the breaking point(s) of the seam alsointo the remaining volume of the airbag, which is substantially notassociated with the thorax area of the airbag, and thus maysubstantially completely fill the airbag. This concept according to theinvention may be applied to airbags having a thorax protection for oneor more passenger rows. In accordance with the invention, the newlydeveloped airbag is suited especially for vehicles having up to threerows of seats, with the airbag according to an embodiment of theinvention being adapted to extend over all three rows of seats. In thiscase, it has turned out to be of advantage when the filling of theairbag is carried out substantially centrally with respect to thelongitudinal extension of the airbag, i.e. an inflator is arrangedsubstantially in the center of the longitudinal extension of the airbag.Alternatively, the airbag according to the invention may also extendover two passenger rows. Moreover, according to the invention it ispossible to use a separate airbag for each seat row which may thus beused also in vehicles having two, three and more rows of seats such as acoach, for example. Especially the concept according to the invention issuited for airbags extending over one or two passenger rows. In thiscase, according to the invention there is preferred the combined designof an airbag according to the invention which extends jointly over thefront seat row and the rear seat row. In this case, the inflator may bearranged either in the A-pillar, or in the B-pillar or C-pillar of thevehicle. According to an alternative embodiment, the use of individualairbags for the protection of the passengers in the front and rear seatrows is possible according to the invention. If the curtain airbag isprovided for protecting the rear passengers of a vehicle, the inflatormay be arranged, for example, in the C-pillar of the vehicle.Furthermore, the inflator/propellant utilized jointly with the novelairbag according to the invention can also be arranged at an angle, e.g.at an angle of preferably 90°, with respect to the deployment plane ofthe curtain airbag, i.e. in a roof plane of the vehicle, for example.Consequently, the novel airbag system according to the invention isespecially suited for conventional sedans or station wagons having oneor two rows of seats, but especially also for MPV, minivans, vans,pickups and coaches as well as trucks.

With the aid of the airbag design according to the invention, it ispossible by all variants presented within the scope of this invention toeliminate any previous problems in deploying curtain airbag systemsincluding a thorax protection in which the gas during deployment hasbeen distributed in a non-directed manner starting from the inflator.Furthermore, the airbag design according to the invention offers theimportant and substantial advantage vis-à-vis previous single- anddouble-chamber systems for curtain airbags which have been utilized sofar to provide a certain thorax protection that the deployment of theairbag according to the invention can be controlled by far bettercompared to said previous single- and double-chamber systems so that anairbag system equipped with such airbag according to the invention in avehicle safety system in the case of crash offers protection for vehicleoccupants which is definitely improved vis-à-vis conventional airbagsystems.

The solution according to the invention is based on the fact that thegas flowing out of the inflator or, resp., propellant at first flowsdirectly into the thorax area of the airbag according to the inventionuntil said thorax area has a particular predetermined degree ofdeployment. At this time the thorax area of a vehicle occupant is thusprotected extremely quickly. When the thorax area of the airbag hasreached a predetermined degree of deployment, the seam(s) provided withpredetermined breaking points tear(s) and the other areas of the volumeof the airbag will fill step-by-step with filling gas in a controlledmanner.

Hence it can be exactly defined by the airbag design according to theinvention which areas of the airbag are filled with filling gas in whichorder of time and space.

According to a further variant according to the invention, the gasguiding device cannot only be designed in the form of one seam or pluralseams being placed inside the airbag, but such gas guiding device canalso be present, as mentioned before, as a tubing system extendinginside the airbag and serving for distribution of the filling gas in theairbag. For this purpose, the tubing system is connected, on the onehand, to a gas supply means such as an inflator and, on the other hand,extends with at least one open end into a portion of the airbag providedfor the thorax protection. The tubing system for this purpose may havebranches, for example to fill the respective airbag areas for the sidecurtain airbag system, which are provided for several passenger rows, orto fill plural primary filling zones in a portion of the airbag whichare associated with only one seat row. In this context, it is alsopossible to feed a primary filling zone of the airbag according to theinvention of two, for instance opposed, airbag portions with fillinggas. Equally it is provided according to the invention that in an airbagaccording to the invention two primary filling zones are provided one ofwhich protects the thorax and another one protects the head area.

Furthermore, the tubing system can be configured so that the filling gasis guided through the tube initially into the respective portions of theairbag provided for the thorax protection and then starting from theseportions extends into the residual volume of the airbag. In accordancewith a variant according to the invention of such tubing system, thelatter may also be formed so that the gas guiding tube tears uponcertain deployment of the airbag at one or more positions so that gascan escape from the gas guiding tube and can fill the residual airbagvolume. A delimitation of the gas guiding tube may be formed, forexample, by one or more seams resulting from the fact that inner wallsof the airbag are interconnected in accordance with a gas guidingdevice. This seam may have predefined seam characteristics and may beconfigured so that it will burst in the case of a predefined inflatingand, resp., deployment volume of the airbag.

An airbag according to the invention thus cannot only be filled in awell-defined manner from the bottom to the top, i.e. in the verticaldirection, but also from the front to the back, i.e. in the horizontaldirection so that, as desired, a back area of a vehicle occupant or anabdominal area of the vehicle occupant is protected in a specific mannerprimarily, i.e. more quickly, or secondarily, i.e. subordinately. Inthis respect, the airbag according to the invention may be selected tobe specifically combined for a respective vehicle and its driver withconsideration of his/her figure and mounted into the vehicle.

Moreover, the invention relates to an aspect of using an airbagaccording to the foregoing remarks for an airbag system, especially aside curtain airbag system, as well as a method aspect for filling anairbag, wherein starting from a gas supply orifice gas is introducedinto the airbag using a gas guiding device according to the foregoingdescription, wherein prior to feeding a secondary filling zone at firstone or several primary filling zone(s) is/are filled substantiallycompletely with gas.

According to an embodiment of the method, in the course of feeding thesecondary filling zone with gas at least one separation, especially atleast one seam and/or one tube, is broken between the primary fillingzone and the secondary filling zone of the chamber.

According to the invention, the separation is broken so far that theairbag interior defines one single chamber in the deployed, i.e.substantially completely filled state of the airbag.

The advantages of the airbag and, respectively, airbag system accordingto the invention thus can be summarized as follows. By way of the airbagdesign according to the invention it is possible to fill a single-,double- or multi-row airbag very quickly so that the thorax area of avehicle occupant is protected in an extremely rapid manner. Thedeployment of the airbag according to the invention is more targeted ascompared to airbags known from the state of the art, namely in terms ofboth time and space. Due to the configuration of the airbag according tothe invention as a single-chamber system, both the deployment and thefilling of the airbag according to the invention is optimized vis-à-vispreviously known airbags. If the airbag according to the invention is inthe form of a single-row airbag, it is moreover possible to position anynumber of said airbags, for example in a coach, one behind the other,wherein each of said airbags offers the advantages according to theinvention. These include, inter alia, the possibility of using a smallinflator which results in a lower weight of the airbag system. This isadvantageous especially with respect to previous curtain airbag systemswhich required a second airbag for a thorax protection.

Further embodiments of the invention will be resulting from thesubclaims.

BRIEF DESCRIPTION OF THE DRAWINGS

Hereinafter the invention will be described by way of embodiments whichwill be explained in detail by way of the pictures, in which:

FIGS. 1a to 1d show state-of-the-art airbag systems in a schematicrepresentation;

FIG. 2 shows a first embodiment of an airbag according to the inventionin a schematic sectional view;

FIG. 3 shows a second embodiment of an airbag according to the inventionin a schematic sectional view;

FIG. 4 shows a third embodiment of an airbag according to the inventionin a schematic sectional view;

FIG. 5 shows a fourth embodiment of an airbag according to the inventionin a schematic sectional view;

FIG. 6 shows a fifth embodiment of an airbag according to the inventionin a schematic sectional view;

FIGS. 7a to 7f show a schematic representation of an airbag according tothe invention in a sectional view having differently arranged gas supplyorifices and inflators in accordance with a further embodiment of theinvention;

FIGS. 8a to 8f show a schematic representation of an airbag according tothe invention in a sectional view having differently arranged gas supplyorifices and inflators according to a further embodiment of theinvention;

FIGS. 9a to 9f show a schematic representation of an airbag according tothe invention in a sectional view having differently arranged gas supplyorifices and inflators according to a further embodiment of theinvention; and

FIGS. 10a to 10f show a schematic representation of an airbag accordingto the invention in a sectional view having differently arranged gassupply orifices and inflators according to a further embodiment of theinvention.

DESCRIPTION

FIGS. 1a to 1d show airbag systems 20 known from the state of the arthaving no thorax protection or a thorax protection insufficientespecially for children. The airbag system 20 according to FIG. 1a isdesigned merely for the respective front seats, while the airbag system20 according to FIG. 1b extends over the rear and front seat rows,wherein in both cases no thorax protection is ensured, however, as theseside curtain airbag systems 20 do not extend sufficiently far downwards.This applies mutatis mutandis to the side curtain airbag system 20according to FIG. 1c which, although including a small separate airbagfor each of the rear and front seat rows which offers protection for thepelvis and the thighs, again does not ensure any thorax protection.Although the side curtain airbag system 20 according to FIG. 1d knownfrom the state of the art offers thorax protection for the back seats,wherein the part of that airbag system 20 provided for the back seatsincludes a double-chamber system, also this side curtain airbag system20 does not exhibit any thorax protection for the respective frontseats, however.

The embodiments of FIGS. 2-10F achieve objects of the invention by wayof an airbag 10, especially for a side curtain airbag system 20, whereinthe airbag includes an airbag interior 30 defining one single chamber 40in the deployed state of the airbag, the chamber having at least one gasguiding device 50 by which the chamber is divided into at least oneprimary filling zone 41 and at least one secondary filling zone 42.

In accordance with a preferred embodiment of the invention, this iseffectuated in that the gas guiding device 50 is configured so that itforms a separation, namely a separating device such as a separating wallor a separating seam between the primary filling zones 41 and thesecondary filling zones 42 or, respectively, between the primary fillingzone 41 and the secondary filling zone 42.

The gas guiding device 50 is formed in that at least two inner wallportions 12 of the airbag 10 facing each other and being associated witheach other are interconnected directly by a seam 52 or by means of aspacer, especially by means of a spacer belt 53, preferably in adetachable manner.

The connection of the inner wall portions 12 of the airbag 10 associatedwith each other is realized, according to the invention, by means of theseam 52 which may be a glued seam and/or a sealed seam and/or a stitchedseam. In the case of use of the spacer belt 53, the respective innerwall portions 12 of the airbag 10 are not connected directly but via thespacer belt, wherein the respective longitudinal sides and,respectively, longitudinal edges of the spacer belt 53 are againconnected by means of seams, which again may be a glued seam and/or asealed seam and/or a stitched seam, to the pertaining, i.e., associated,inner wall portions of the airbag.

FIG. 2 illustrates a first embodiment of an airbag 10 according to theinvention in a schematic sectional view. The airbag 10 comprises anairbag interior 30 including a chamber 40 which is divided into aprimary filling zone 41 and a secondary filling zone 42 by a gas guidingdevice 50 in the form of a seam 52. The airbag 10 includes a gas supplyorifice 60 connected to an inflator or any other gas supply means.Through said gas supply orifice 60 filling gas flows into the airbaginterior 30 in the operating state of the airbag 10 and spreads alongthe initial gas flow direction 90 at first non-directed into the gasinterior 30, but is guided immediately afterwards by the gas guidingdevice 50 in the form of a seam 52 along the primary gas flow direction100 represented as a bold straight arrow into the primary filling zone41. This primary filling zone 41 deploys, according to the invention, upto a predefined degree, wherein upon reaching such degree and anaccompanying predefined deployment volume bursting of the seam 52 isinitiated, which seam then tears at least partly or completely andenables a secondary gas flow direction 200 represented as a bold curvedarrow along which the secondary filling zones 42 of the airbag 10 arefilled. Thus the airbag 10 according to the invention of FIG. 2 isfilled at first in its primary filling zone 41 represented at the bottomof the picture. This primary filling zone 41 substantially serves forthe protection of a thorax area of a vehicle occupant, but it can alsobe continued up to the pelvis and thigh area, if desired. As is evidentfrom FIG. 2, that airbag is formed for two seat rows, wherein the gassupply orifice 60 and the inflator are arranged in the rear part of theairbag 10 and are accommodated in the C-pillar of the vehicle.

FIG. 3 illustrates a second embodiment of an airbag 10 according to theinvention in a schematic sectional view substantially corresponding tothe embodiment shown in FIG. 2, with the difference that the airbag 10according to FIG. 3 is not filled from behind, i.e. starting from theC-pillar of the vehicle, but centrally, i.e. starting from the B-pillarof the vehicle, with filling gas. This embodiment offers the advantageof filling gas being adapted to flow uniformly into the portion of theairbag 10 associated with the front seat row and the rear seat row dueto gas entry in the central area of the airbag 10. According to FIG. 3,too, the filling gas initially flows along a primary gas flow direction100 first into a primary filling zone 41 of the airbag interior 30,which again and corresponding to FIG. 2 is designed as one singlechamber, and only after bursting of the gas guiding device 50 in theform of a seam 52 it flows into the secondary filling zone 42.

FIG. 4 shows a third embodiment of an airbag 10 according to theinvention in a schematic sectional view, wherein the gas supply orifice60 is arranged again in the rear area of the airbag 10. In this context,it is emphasized that the gas supply orifice 60 basically cannot only bearranged in the rear area of the airbag 10 and, resp., in the centralarea of the airbag, but on principle may also be arranged in the frontarea of the airbag 10, namely whenever the inflator and, resp., the gassupply means, is not intended to be provided in the C-pillar or theB-pillar but in the A-pillar of the vehicle. It is basically alsopossible to accommodate the inflator in the roof area of the vehicle andto design a gas supply orifice 60 on the airbag according to theinvention corresponding to the desired arrangement of the inflator.

According to FIG. 4, the filling gas flows along an initial gasadmission direction 90 through the gas supply orifice 60 into the airbaginterior 30 which is in the form of one single chamber 40. The gasinitially enters into a tubing system 54 which is formed by providing,on the one hand, a tube section of the tubing system 54 tightly arrangedon the inlet opening 55 for the filling gas which interacts with a seam52 interconnecting the inner wall sides of the chamber 40 of the airbaginterior 30. The interaction between the tube section and the seam 52results in a tubing system 54 which at its lower end includes an outletopening 56 through which the filling gas may flow, upon filling the sidecurtain airbag system 20, along a primary gas flow direction 100 intothe primary filling zone 41 of the airbag 10. After the primary fillingzone 41 of the airbag 10 has widened and deployed up to a predefineddegree, the seam 52 bursts along the predetermined breaking point 57 andenables the filling gas to flow along the secondary gas flow direction200 into the secondary filling zone 42 of the airbag 10.

FIG. 5 illustrates a fourth embodiment of an airbag 10 according to theinvention in a schematic side view, wherein again a gas supply orifice60 connected to an inflator is provided in the rear part of the airbag10. Through the gas supply orifice 60 gas flows along an initial gasflow direction 90 through an inlet opening 55 into a tubing system 54which extends in the interior 30 of the airbag 10. The airbag 10according to FIG. 5 is an airbag for two seat rows. According to FIG. 5,the tubing system 54 extends starting from the inlet opening 55 into thethorax protection zone for each of the front and rear seat rows andthere includes respective outlet openings 56 through which the fillinggas can flow along a primary gas flow direction 100 into the respectiveprimary filling zone 41. After the filling gas has escaped from therespective outlet opening 56, the filling gas initially spreads in theprimary filling zone 41 and from there subsequently flows into thesecondary filling zone 42 of the side curtain airbag system 20.

FIG. 6 shows another, i.e. fifth embodiment of an airbag 10 according tothe invention in a schematic sectional view, wherein a tubing system 54is provided through which filling gas is guided from an inlet opening 55to two respective outlet openings 56 in the respective primary fillingzones 41 of the airbag 10 which are associated with a respective thoraxprotection zone for a front and a rear seat row of the side curtainairbag system 20. Also in this case, the filling gas initially flowsthrough the outlet openings 56 into the respective primary filling zone41 and only afterwards, i.e. only after the primary filling zone 41 hasbeen filled at least partly, into the secondary filling zone 42 of theairbag 10.

Each of the airbags 10 schematically shown in FIGS. 7a to 10f are formedas single-row airbags 10, wherein the respective pictures inter aliadiffer by the fact that the schematically shown airbags 10 designatedwith a and b in the pictures include a gas supply orifice 60 which inthe driving and mounting direction is formed and arranged at the front,whereas the airbags 10 designated with the letters c and d include a gassupply orifice 60 which in the driving and mounting direction is formedand arranged centrally, and the airbags 10 designated with the letters eand f include a gas supply orifice 60 which in the driving and mountingdirection is formed on the rear side. An inflator is associated witheach of the gas supply orifices 60.

According to FIGS. 7a to 10f , the filling gas flows along an initialgas admission direction 90 through the gas supply orifice 60 into theairbag interior 30 which is in the form of one single chamber 40.

In each of the FIGS. 7a to 7f an airbag according to the invention isshown in a respective schematic sectional view, wherein filling gasflows through a gas supply orifice 60 into a tubing system 54 arrangedwithin the airbag 10 that serves as a gas guiding device 50. Accordingto FIGS. 7a, 7b, 7e and 7f , the tubing system 54 includes two outletopenings 56 through which in the operating state, i.e. during a fillingoperation of the airbag 10, the filling gas flows initially into twoprimary filling zones 41 associated with the thorax area and the headarea so that, in a case of crash, first the thorax area as well as thehead area of a vehicle occupant are protected. In the case of a centralfilling of the airbag 10 according to the invention, as schematicallyshown in FIG. 7c and FIG. 7d , the tubing system 54 arranged in theairbag 10 includes a total of three outlet openings 56 through which thefilling gas can initially flow into the primary filling zones 41 of theairbag 10 according to the invention. A filling of the secondary fillingzones 42 does not take place before the filling gas has flown along theprimary gas flow direction 100 into the primary filling zone 41 and fromthere outpours into the secondary filling zones 42.

The embodiment of an airbag according to the invention shown in FIGS. 9ato 9f substantially differs from the embodiment shown in FIGS. 7a to 7fin that the airbag according to the invention as illustrated in FIGS. 9ato 9f includes a tubing system 54 which has only one single outletopening 56 which is associated with the primary filling zone 41 and withthe thorax area. According to this embodiment, the filling gas flowsfrom the gas supply orifice 60 into the tubing system 54 and leaves thelatter along a primary gas flow direction 100 through the outlet opening56, wherein the first filling zone 41 of the airbag 10 is inflated andthus deployed. After the fill volume of the airbag 10 has reached apredefined level in the first filling zone 41, the filling gas flowsinto the secondary filling zone(s) 42 along a secondary gas flowdirection 200.

According to FIGS. 8a to 8f , the airbag 10 according to the inventionincludes a gas guiding device 50 which in the case of front-side orrear-side filling is configured as a seam 52 and in the case of centralfilling is configured as two seams 52 defining a channel. Along the gasguiding device 50 the flowing filling gas is guided along a primary gasflow direction 100 first into the first filling zone 41, until thelatter has a predetermined fill volume as well as a predeterminedpressure. Upon reaching said fill volume and/or the predeterminedpressure, the gas guiding device 50 in the form of a seam 52 will tearso that the filling gas can flow along the secondary gas flow direction200 into the secondary filling zone 42. In this way, the filling gasinflowing from the gas supply orifice 60 at first along an undefinedinitial gas admission direction 90 does not spread in the airbag 10according to the invention in a non-directed and turbulent manner, as inthe previous state of the art, but flows along the gas guiding device 50in a directed manner first into the primary filling zone 41 and onlyafterwards into the secondary filling zone 41. As is indicated in FIGS.8a to 8f by the hatched seam 52, according to the invention the seam 52is not designed to be completely gas-tight but permits a minor gaspassage, when the outflowing filling gas flows along the gas guidingdevice 50. In this way, the secondary filling zone 42 can slightlydeploy already before the seam 52 bursts, which, on the one hand,contributes to improved deployment of the curtain airbag per se as wellas to controlled inflation of the secondary filling zone 42 afterfilling the first filling zone 41.

In FIGS. 10a to 10f another embodiment of an airbag 10 according to theinvention is illustrated in a schematic sectional view in which thefilling gas coming from the gas supply orifice 60 flows into a tubingsystem 54 formed of seams 52 that may burst at a predefined pressure. Inaccordance with the embodiments shown in FIGS. 10a to 10f it isillustrated in which way a tubing system 54 can be formed of seams 52,wherein the tubing system 54 will tear from a particular fill volume ofthe airbag 10 and, resp., of the primary filling zone thereof bybursting of the seams 52 so that the inflowing filling gas then does notonly flow along a primary gas flow direction 100 through the outletopening 56 but also outpours through the burst seams 52 into thesecondary filling zone(s) 42. The respective gas flow directions areschematically indicated in FIGS. 7a to 10f by respective arrows.

Each of the airbags 10 according to the invention schematicallyrepresented in FIGS. 2 to 10 f is provided with module fastenings 1 anda strap or belt 2 which serve for mounting the respective airbags 10 onor in a vehicle.

It is pointed out in this context that all afore-described partsconsidered per se and in any combination, especially the details shownin the drawings, are claimed to be essential to the invention.Modifications of the same are known to those skilled in the art.

LIST OF REFERENCE NUMERALS

-   1 module fastening-   2 strap or belt-   10 airbag-   20 side curtain airbag system-   30 airbag interior-   40 chamber-   41 primary filling zone-   42 secondary filling zone-   50 gas guiding device-   52 seam-   54 tubing system-   55 inlet opening-   56 outlet opening-   57 predetermined breaking point-   60 gas supply orifice-   90 initial gas admission direction-   100 primary gas flow direction-   200 secondary gas flow direction

Having described the invention, the following is claimed:
 1. A curtainairbag for a vehicle, comprising: overlying airbag panels configured todefine a single inflatable chamber, the chamber comprising a firstlongitudinal portion configured to protect a first occupant seated inthe vehicle, and a second longitudinal portion extending in alongitudinal direction from the first longitudinal portion andconfigured to protect a second occupant seated in the vehicle in adifferent row than the first occupant; and a gas guiding device thatdefines in the first longitudinal portion of the chamber a lower primaryfilling zone and an upper secondary filling zone, wherein the secondaryfilling zone is configured for head protection when inflated anddeployed, and the primary filling zone is configured for thoraxprotection when inflated and deployed; wherein the first longitudinalportion is configured so that the primary filling zone has a lowerextent in the vehicle than a lowermost extent of the second longitudinalportion, wherein the gas guiding device is configured to arrange theprimary filling zone spatially more distant from a gas supply orificethan the secondary filling zone and fluidly less distant from the gassupply orifice than the secondary filling zone, and to guide gassupplied into the chamber first into the primary filling zone for thoraxprotection, and thereafter into the secondary filling zone for headprotection once the gas supplied into the primary filling zone reaches aprimary filling level.
 2. The curtain airbag of claim 1, wherein duringfilling of the curtain airbag, the primary filling zone is filled withgas before the secondary filling zone.
 3. The curtain airbag of claim 1,wherein the gas guiding device comprises at least one of a glued seam,sealed seam, and a stitched seam, and wherein the at least one of aglued seam, sealed seam, and stitched seam have different seamresistances along their lengths.
 4. The curtain airbag of claim 3,wherein the at least one of a glued seam, sealed seam, and stitched seamhas a rupturable portion that is configured to rupture once the curtainairbag reaches a predefined pressure.
 5. The curtain airbag of claim 1,wherein the gas guiding device comprises a channel having an inletopening and an outlet opening, the inlet opening being in fluidconnection with a gas supply orifice of the curtain airbag, the outletopening ending in the primary filling zone.
 6. The curtain airbag ofclaim 1, further comprising a gas supply orifice arranged centrally withrespect to a longitudinal extent of the curtain airbag.
 7. A vehiclesafety system, comprising: the curtain airbag of claim 1; at least onesensor unit for detecting data; and an electronic decision-making unitwhich is adapted, while incorporating the data detected by the sensorunit, to define the presence of a trigger case for inflating the curtainairbag and/or to send a trigger signal for inflating the curtain airbag.8. The curtain airbag of claim 1, wherein the curtain airbag has agreater length in a vertical direction at the first longitudinal portionthan at any other longitudinal portion of the curtain airbag, thevertical direction being perpendicular to the longitudinal direction. 9.The curtain airbag of claim 1, wherein the primary filling zone has alength in the longitudinal direction that is less than the a length ofan entirety of the curtain airbag.
 10. The curtain airbag of claim 1,wherein the primary filling zone of the first longitudinal portion doesnot extend into the second longitudinal portion.